- African manatee
- Amazonian manatee
- American manatee
- Atlantic blackfish
- Atlantic grey seal
- Atlantic spotted dolphin
- Atlantic white-sided dolphin
- Bagwhale
- Baltic grey seal
- Bay whale
- Bearded seal
- Beluga
- Beluga whale
- Biscayan right whale
- Black right whale
- Blackfish: can refer to Peponocephala electra, Globicephala macrorhynchus, Globicephala melas (whales), or Pseudorca crassidens (dolphin)
- Bladdernose seal
- Blainville’s beaked whale
- Blue rorqual
- Blue whale
- Bornean dolphin
- Bowhead
- Bridled dolphin
- Bridled porpoise
- Bryde’s whale
- Bunch whale
- Caa’ing whale
- Cape dolphin
- Caribbean manatee
- Common blackfish
- Common bottlenose dolphin
- Common minke whale
- Common otter
- Common pilot whale
- Common porpoise
- Common seal
- Cuvier’s beaked whale
- Cuvier’s porpoise
- Davidson’s whale
- Dolphin
- Dugong
- Dwarf minke whale
- Dwarf sperm whale
- Electra dolphin
- Eurasian otter
- Eurasian river otter
- European otter
- False killer whale
- Fin whale
- Finback
- Fraser’s dolphin
- Fraser’s porpoise
- Gamin
- Gervais’ beaked whale
- Grampus
- Gray grampus
- Gray’s beaked whale
- Great blue whale
- Great northern rorqual
- Grey seal
- Grey whale
- Gulf Stream spotted dolpin
- Harbour porpoise
- Harbour seal
- Harp seal
- Hawaiian blackfish
- Herring hog
- Hooded seal
- Horsehead
- Hump
- Hump whale
- Humpback whale
- Hunch
- Hunchback whale
- Jumper
- Killer whale
- Killer-trasher
- Least rorqual
- Lesser finback
- Little piked whale
- Long-finned pilot whale
- Long-snouted dolphin
- Manatee
- Many-toothed blackfish
- Mediterranean monk seal
- Melonhead
- Melon-headed dolphin
- Melon-headed whale
- Mermaid
- Minke whale
- Narrow-snouted dolphin
- Narwhal
- North Atlantic right whale
- Northern bottlenose whale
- Northern minke whale
- Northern right whale
- Orca
- Ostende whale
- Otter
- Pikehead whale
- Polar bear
- Pollack whale
- Porpoise
- Pothead
- Puffing pig
- Pygmy sperm whale
- Right whale
- Ringed seal
- Risso’s dolphin
- Risso’s grampus
- Rough-toothed dolphin
- Roundhead
- Sarawak dolphin
- Sardine whale
- Sea canary
- Sea cow: can refer to Trichechus manatus, Dugong dugon, or in general to sea cows
- Sea elephant
- Sea lion
- Sea pig
- Sea unicorn
- Seal
- Sei whale
- Sharp-headed finner whale
- Short-beaked common dolphin
- Short-finned pilot whale
- Sibbald’s rorqual
- Social whale
- Sowerby’s beaked whale
- Sperm whale
- Spermacet whale
- Square flipper seal
- Squareflipper
- Striped dolphin
- Sulphurbottom whale
- Summer whale
- Sword grampus
- Swordfish
- True’s beaked whale
- Trumpo
- Ugruk
- Walrus
- West Indian manatee
- Whale
- White fish
- White whale
- White-beaked dolphin
- White-headed grampus